Treating cervical myelopathy

When a patient shows signs of cervical spinal cord dysfunction, we say that the patient has cervical myelopathy. Cervical myelopathy is commonly caused by compression from degenerative changes in the bone, discs, and ligaments of the spine.

Cervical myelopathy can occur from one or multiple areas of spinal cord compression. Findings will be similar in both cases. Spinal compression can develop over years or over hours, so the presentation can be very slow at times, and acute in other cases.

When evaluating any cervical spine condition, even simple neck pain, start with a myelopathy exam. Cervical myelopathy typically presents with an array of upper motor neuron findings and sensory findings such as loss of proprioception and a sensory level. In some cases, there may be some lower motor neuron findings in the upper extremities (such as atrophy). But, usually, there will be a predominance of upper motor neuron findings.

If you do find upper motor neuron findings on the exam, do the findings involve the arms as well as the legs? Theoretically, a spinal cord process should involve neurological findings in both, but this is not always the case.

If only the legs and lower torso are involved, the region of pathology could be in the thoracic spine—but don’t count on it! It still may be coming from the cervical spine. Cervical myelopathy is far more common than thoracic, but it can be hard to tell the difference clinically if the arms are unaffected. If you suspect a thoracic pathology (but cannot find one) don’t forget to look for trouble in the neck!

Additional testing for cervical myelopathy

Magnetic resonance imaging

If you suspect cervical myelopathy, you should order non-contrast magnetic resonance imaging (MRI) of the cervical spine. If there are only lower extremity findings, include a thoracic spine MRI as well.

If you don’t see a structural lesion on MRI, you should consider other diseases such as multiple sclerosis (MS), vitamin B12 deficiency, acquired immunodeficiency syndrome (AIDS) myelopathy, syphilis, and amyotrophic lateral sclerosis (ALS) into your differential diagnoses.

The non-contrast MRI should catch findings such as severe stenosis, disc herniation, tumor, fracture or dislocation, epidural abscess, hematoma, transverse myelitis, and syrinx. In cases of definitive myelopathy (but with no findings on non-contrast MRI), a contrast MRI, other diagnostic tests (e.g., serum studies), and a spinal tap may be indicated.

If the patient has relatively mild deficits and they report that their symptoms haven’t changed much over the past couple of months, don’t feel compelled to order an emergent MRI. However, MRI should be completed within one to two weeks.

If the deficits are progressing day to day, order an emergent MRI. An emergent MRI would also be indicated if the patient is profoundly myelopathic (e.g., they cannot walk or stand up). In this case, get the patient imaged as quickly as possible because any lost spinal cord function is not guaranteed to improve.

Computed tomography myelogram

If MRI is not available, computed tomography (CT) myelogram is a viable option. This requires a lumbar puncture and the injection of contrast material into the thecal sac which is then scanned on CT. This study will never match MRI in its fidelity and precision, so always go with MRI if possible.

Electromyogram

Electromyograms (EMGs) are not beneficial in straightforward myelopathy cases. But, EMGs can be useful for evaluating other pathologies such as ALS.

Lateral flexion-extension x-rays

Lateral flexion-extension x-rays should be obtained to rule out abnormal movement between the vertebrae. Sometimes, spinal cord compression may not be obvious on a static MRI. With flexion-extension x-rays, spinal column instability may be discovered alongside dynamic compression of the spinal cord. Thankfully, this is not a common finding.

When should patients have surgery to address cervical myelopathy?

If you see a patient who has moderate to severe stenosis in the cervical spine but no myelopathic findings or symptoms, surgery is generally not recommended. Be wary of surgeons who want to perform prophylactic decompression; there is no evidence that this surgery is beneficial for your patient.

Many patients with definitive spinal stenosis experience no progressive neurological deficits for decades. You may want to caution the patient about high-risk behaviors; sudden jerking of the neck might result in acute spinal cord compression. It’s not necessary to restrict a patient’s activities if they are within reason. For example, you may want to argue against parachute jumping but support bike riding and tennis.

A patient with definitive stenosis (but no neurological findings) should undergo a clinical follow-up every three to six months. If myelopathic findings begin to show, refer to a spinal surgeon immediately.

Patients with mild cervical stenosis and static myelopathic findings can be monitored, but it is advisable to solicit a spine surgeon’s opinion on the patient.

In patients with more than mild stenosis and definitive myelopathy, surgery should be strongly considered since the condition will most likely worsen. Spondylotic myelopathy tends to worsen over time, but not in a linear fashion; it tends to progress in a step-like manner.

What’s involved in surgery for cervical myelopathy?

Surgery for cervical spondylotic myelopathy involves making room for the spinal cord by removing the compressive elements. The spinal cord may be approached through the anterior neck, the posterior neck, or both. Often, the surgery involves some method of instrumentation and fusion.

Fusion is designed to get two or more vertebrae to grow together into one bone. Instrumentation is designed to hold the bones together until they are completely healed. This takes one to two years to complete, at which time the instrumentation can be removed (but seldom is).

Sometimes, the extent of the surgery is quite impressive with large segments of the cervical spine manipulated, with bone fusion and instrumentation extending into the upper thoracic region. This is reasonable in cases of spondylotic myelopathy. Other pathologies may require simple decompression with no instrumentation, usually through the back of the neck (laminectomy).

Why should patients consider surgery to treat cervical myelopathy?

Surgery is effective in arresting the progression of deficits but only moderately effective in improving deficits.

It’s appropriate to give your patient the 30–30–30 discussion. That is, 30% of patients will experience marked improvement with a near-total resolution of myelopathic signs, 30% will experience some improvement (but not complete), and 30% will experience no improvement or some deterioration.

Surgery is certainly not risk-free. Most experienced surgeons have had cases where the surgery went beautifully, but the patient awoke with worse deficits. The more the decompression and instrumentation, the greater the risks. However, in many cases, there is no good alternative!

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